TY - JOUR
T1 - Isospin competitions and valley polarized correlated insulators in twisted double bilayer graphene
AU - Liu, Le
AU - Zhang, Shihao
AU - Chu, Yanbang
AU - Shen, Cheng
AU - Huang, Yuan
AU - Yuan, Yalong
AU - Tian, Jinpeng
AU - Tang, Jian
AU - Ji, Yiru
AU - Yang, Rong
AU - Watanabe, Kenji
AU - Taniguchi, Takashi
AU - Shi, Dongxia
AU - Liu, Jianpeng
AU - Yang, Wei
AU - Zhang, Guangyu
N1 - Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - New phase of matter usually emerges when a given symmetry breaks spontaneously, which can involve charge, spin, and valley degree of freedoms. Here, we report an observation of new correlated insulators evolved from spin-polarized states to valley-polarized states in twisted double bilayer graphene (TDBG) driven by the displacement field (D). At a high field |D | > 0.7 V/nm, we observe valley polarized correlated insulators with a big Zeeman g factor of ~10, both at v = 2 in the moiré conduction band and more surprisingly at v = −2 in the moiré valence band. Moreover, we observe a valley polarized Chern insulator with C = 2 emanating at v = 2 in the electron side and a valley polarized Fermi surface around v = −2 in the hole side. Our results demonstrate a feasible way to realize isospin control and to obtain new phases of matter in TDBG by the displacement field, and might benefit other twisted or non-twisted multilayer systems.
AB - New phase of matter usually emerges when a given symmetry breaks spontaneously, which can involve charge, spin, and valley degree of freedoms. Here, we report an observation of new correlated insulators evolved from spin-polarized states to valley-polarized states in twisted double bilayer graphene (TDBG) driven by the displacement field (D). At a high field |D | > 0.7 V/nm, we observe valley polarized correlated insulators with a big Zeeman g factor of ~10, both at v = 2 in the moiré conduction band and more surprisingly at v = −2 in the moiré valence band. Moreover, we observe a valley polarized Chern insulator with C = 2 emanating at v = 2 in the electron side and a valley polarized Fermi surface around v = −2 in the hole side. Our results demonstrate a feasible way to realize isospin control and to obtain new phases of matter in TDBG by the displacement field, and might benefit other twisted or non-twisted multilayer systems.
UR - https://www.scopus.com/pages/publications/85131474030
U2 - 10.1038/s41467-022-30998-x
DO - 10.1038/s41467-022-30998-x
M3 - Article
C2 - 35672329
AN - SCOPUS:85131474030
SN - 2041-1723
VL - 13
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 3292
ER -